Conventionally, a peripheral device such as postprocessing device and large-capacity paper feeder (hereinafter referred to as option device) would be fitted to a main unit of an image forming device in response to user's demand.
Because of this, the main unit of the image forming device includes a communication part with the option device, e.g. a paper-receiving port for guiding sheets of paper received from the option device and a paper-feeding port for guiding sheets of paper to the option device. Also, the image forming device includes electrically connecting section and other sections relating to communication and power supply between the option device and the image forming device.
However, in the case where the option device is not fitted to the image forming device, it is necessary to improve the appearance of the image forming device and to prevent accidents at the communication part and other part. Therefore, the attaching section, such as the communication part and the electrically connecting section (a connecting part between the main unit of the device and the option device), is covered with an external cover for covering, a cover provided as an outer surface of the image forming device, or the like so that the attaching section is invisible or the attaching section is not usable.
In such an image forming device, after detaching the external cover for covering, or cutting off a portion of a cover provided as an outer surface of the image forming device as disclosed in Japanese Laid-Open Patent Application No. 10-133443/1998 (Tokukaihei 10-133443; published on May 22, 1998), the option device is fitted to the main unit of the image forming device.
In Japanese Laid-Open Patent Application No. 10-133443/1998, the cut-off portion, which serves another function, is reused without being thrown away. With this arrangement, effective use of resources is attempted.
However, in an image forming device as described in Japanese Laid-Open Patent Application No. 10-133443/1998, the following problem arises when the image forming device is used independently from the option device: when a portion of the cover provided as the outer surface of the image forming device is cut off, the outer surface of the image forming device is kept exposed with its original form lost, degrading appearance of the image forming device.
Further, when the cover provided as the outer surface of the image forming device is replaced with a new one, the problem that maintenance cost occurs arises.
Japanese Laid-Open Patent Application No. 2002-182441 (Tokukai 2002-182441; published on Jun. 26, 2002) discloses that parts removed from a main unit of a device before the option device is fitted to the main unit are made usable as a functioning component of the option device. In addition, Japanese Laid-Open Patent Application No. 2002-182441 discloses that the parts removed from the main unit of the device can be reattached to the main unit of the device after the option device is separated from the main unit of the device. Note that, as a usage example of the parts removed from the main unit of the device as the functioning component of the option device, given is a paper stopper for a paper feed tray. However, although the parts removed from the main unit of the device can be used as a functioning component of the option device, the removed parts are a supplementary component of the option device, not essential component for the option device. Therefore, some users might not use the parts removed from the main unit of the device as a functioning component of the option device. On this account, there is the possibility that the parts removed from the main unit of the device would be lost when the option device is fitted to the main unit of the device.
Further, Japanese Laid-Open Patent Application No. 2000-270133 (Tokukai 2000-270133; published on Sep. 29, 2000) discloses that in the image forming device, an external cover corresponding to the part where an additional option device is fitted is a partial cover being attachable/detachable to/from the external cover, and the partial cover can be attached in an inverted position in the vertical direction or horizontal direction, depending on whether or not the option device is fitted to the image forming device. However, the partial cover has only the function as a cover when the option device is attached or is not fitted to the image forming device. Further, in the image forming device, when the part where the additional option device is fitted is located between the image forming device and the additional option device, the attaching part is covered by the option device. This eliminates the necessity to cause the partial cover to function as a cover when the option device is fitted, and the partial cover might not be attached to the image forming device, depending on a user. Because of this, there is the possibility that the partial cover would be lost.